In recent years, music playing systems using computers are rapidly becoming popular. Generally, the music playing systems are aimed at enjoying composing and arranging music and require musical expertise and skills.
On the other hand, systems have also been proposed that are easy to use and entertaining, such as those visualizing scores as images by replacing the scores with graphics and colors, and those synchronizing music with changes in images.
As an example of such systems, a music playing system has been proposed that includes: a pen-shaped input device for inputting coordinate information about a drawn picture; a display device for displaying the coordinate information input from the pen-shaped input device; a sound source device for outputting sound signals corresponding to the coordinate information input from the pen-shaped input device; and a main control device for controlling the display device and the sound source device based on the coordinate information input from the pen-shaped input device. According to this music playing system, tones of a musical instrument used are replaced with colors on an input screen, and a user freely selects colors among color variations and puts the colors on a display screen. Thus, in addition to the pleasure of listening to sounds, this system is supposed to provide visual pleasure (see Patent Document 1).
However, in the above music playing system, a sound signal corresponding to a position where the pen is placed for drawing is a sound signal assigned to the coordinate position. Sound signals for respective coordinate positions are generated and recorded in advance when a picture is drawn, and thereafter the drawn picture is traced to reproduce the sound signals for the coordinate positions. That is, rather than sound signals generated by drawing a picture, sound signals for coordinate positions are reproduced based on where the pen is placed on the screen during tracing of the drawn picture. Therefore, it is actually impossible to generate arbitrary sounds based on an arbitrarily drawn picture, and the pen should be operated as defined by positions on the screen. In addition, the pen must be moved at exactly the same positions on the screen in order to reproduce music.
A sound generating method has been proposed that includes an image displaying step of displaying input images in order of input in a drawing area having a preset coordinate system, and a sound generating step of generating a sound corresponding to the coordinates of an image portion being displayed in the coordinate system. The coordinate system is configured with a first coordinate axis determining the sound pitch and a second coordinate axis determining the sound volume balance between the right and left. According to this sound generating method, it is supposed that the reproduced drawing and sounds can be made identical with the input drawing and sounds (see Patent Document 2). A mouse click operation adds a tempo factor, so that a phrase is generated.
However, in the above sound generating method (Patent Document 2), a generated sound is a sound having the pitch and volume assigned to a coordinate position (a coordinate point). That is, uniquely obtaining a sound having a specific pitch and volume requires inputting a specific coordinate point in the plane coordinate system. In addition, a generated phrase is determined with a mouse operation at a specific coordinate point in the plane coordinate system. In these senses, as in the above-described music playing system (Patent Document 1), it can be said that this sound generating method (Patent Document 2) has a small degree of freedom with which sounds are generated based on an arbitrarily created drawing.
In this respect, a parameter input apparatus for electronic musical instruments has been proposed for the purpose of improving the operability by using a tablet to input tone parameters and effect parameters for a musical instrument (see Patent Document 3). In this apparatus, operation points on the tablet are sampled and vectors Vk connecting the sampling points Pk (k=0, 1, 2, . . . ) are assumed. A parameter is increased or decreased according to the rotation angle of the direction of a current vector against the direction of a vector V0 obtained at the beginning of the operation. Whether increasing or decreasing the parameter value depends on the rotation direction at the operation point, and the rotation direction at the operation point is detected based on the difference (variation) in the inclination of the vectors.
Patent Document 1: Japanese Patent Laid-Open No. 8 -3350756
Patent Document 2: Japanese Patent Laid-Open No. 2003-271164
Patent Document 3: Japanese Patent Laid-Open No. 6 -175652
However, in the above parameter input apparatus for electronic musical instruments (Patent Document 3), the object controlled based on the vectors is the increase or decrease of values such as the tone parameter. Settings for the tone parameter itself are changed by a parameter input device such as a mode setting switch, which is input means separate from the tablet. Therefore, as in the above-described other conventional art, it can be said that there is a small degree of freedom with which sounds are generated based on an arbitrarily created drawing.
The present invention has been made in view of the above problems, and an object thereof is to provide a sound generating method that allows arbitrarily producing a sound and arbitrarily selecting a drawing color substantially only with drawing operations.